Cleidocranial dysplasia – the Jerusalem Approach: part 1

Published: September 2013

Bulletin
#25 September 2013

Cleidocranial dysplasia – the Jerusalem
Approach: part 1

Introduction

Cleidocranial dysplasia (CCD) is an autosomal
dominant genetic condition or syndrome which is characterized by short stature,
brachycephalic headform, with parietal and frontal bone bossing. The midface is
hypoplastic, giving the appearance of mandibular prognathism, although the
pattern is usually one of maxillary underdevelopment. The sutures of the skull,
particularly the fontanelles, show delayed closure and the presence of numerous
centers of ossification leads to the formation of wormian bones, visible on a
lateral or antero-posterior cephalogram. The clavicles are deficient to varying
degrees and may be totally absent in severe cases, giving the patient a narrow
chest and sloping shoulders.

CCD is unlike most other syndromes, insofar as
the affected individuals have normal intelligence and some even seem to have a higher
level of intelligence than their peers. They do not suffer from physical disability,
pain or tendency to infection as the result of their condition and neither do
they require treatment of any sort in order to improve their lot. Of course,
this is a broad generalization, because each individual patient may show
varying degrees of severity of the specific features of the syndrome or may
exhibit other symptoms not normally associated with CCD. Thus, one of my
patients has bilateral anophthalmia and, while this might occur with any
individual, it seems that apparently unrelated other phenomena may be found
with greater frequency among CCD patients. This is not an evidence-based
statement and merely represents a clinical observation gleaned from the
examination of approximately 35-40 affected individuals over the years, as well
as from literature reports, in which more than 100 other anomalies have been
associated with the above-mentioned major features of CCD.1

Impacted and supernumerary teeth

CCD is perhaps the mother of all conditions in
which impacted teeth figure large on the radar screen. In addition to the
impaction of the teeth of the normal permanent dentition, the patient usually
exhibits unerupted supernumerary teeth, which may number from one or two in one
individual and, in rare instances, to as many as 30 in another. 2 Nevertheless,
the author has seen cases in which there were no extra teeth and, in one
instance, there were congenitally absent maxillary lateral incisors while, in
another, a missing third molar!

The dental aspects of the syndrome are usually
the most significant features and typically exhibit a severely reduced lower
facial height, a concave profile with an edentulous look, over-retained
deciduous teeth well into adulthood, relatively few erupted and severely
displaced permanent teeth, with very poor occlusion. These patients present
with extreme degrees of dental disability.3

In the past and regarding the attitude of
dentists to CCD, wholesale extractions were made of the erupted deciduous
teeth, the impacted teeth of the normal series and of the supernumerary teeth,
with removable and fixed prostheses supported on unerupted or partially erupted
abutment teeth. The results were highly unsatisfactory in the long term and,
because the oral rehabilitation required is extensive and needs to be performed
on relatively young patients, there was the need for repeat and more
comprehensive prosthodontics pursuant to further deterioration of the health of
the existing natural teeth under these restorations, in the years that followed.

Fortunately, the orthodontic and surgical
modality is a modality of treatment which can produce excellent results in
these patients, which is in stark contrast to the prognosis of the treatment of
the other, non-dental and less debilitating aspects of the condition. Only
relatively recently has this modality been considered a viable option for the
treatment of CCD and it is capable of yielding superb results.Nevertheless,
it requires careful planning and is best divided into several logical stages or
phases, each with its own clear goals, aims and direction. 3,4

For the most part, the diagnosis of CCD will
have been made by the pediatrician in the first years of an infant’s life.
Those with a family history of the condition will obviously be diagnosed
earliest, because this fact will have given the parent and doctor advanced
warning of this possibility. Among those without a family history, diagnosis
may not be made until much later because there are relatively few signs and
symptoms that may appear on the surface to indicate abnormality and to
recognize the need for a more focused examination. Certainly, the child’s
physical development may be slower, his/her stature relatively shorter and the
often characteristic facial features relatively unpronounced. But he/she is
usually a bright child, a quick learner, with no behavioral problems and is
socially well-adjusted – attributes which may tend to obscure even the
enquiring mind of the possible existence of a pathologic entity.

So, it is not entirely surprising that, for a
small proportion of patients, the diagnosis of CCD may only have been made much
later, as the follow-up of a dental examination to investigate the complaint of
failure of the deciduous incisors to shed and the permanent incisors to erupt.
This will usually occur at approximately 8 years of age, which is when the
child is the only one in the class at school who does not have new, large, spaced
(and ugly!) anterior teeth. The child is now becoming more and more different
from his/her contemporaries because, in
infancy what previously were minor differences in stature and facial
development, now become aggravated with what must be counted as oral
abnormality, insofar as there is none of the expected physical change that
should have occurred by this time. The deciduous teeth are likely worn down by
attrition, with very short clinical crowns. They are almost completely
invisible in normal expression and inter-personal dialogue, giving the child an
edentulous appearance and the visage of old age.

This bulletin is planned as the first of a
series in which the Jerusalem approach to treatment will be described in its
several stages and phases, with full clinical details. In it we shall present
an introduction to the very young CCD patient and discuss treatment goals and
timing of the first stages in the long haul that will hopefully lead to the
establishment of a complete, functioning and attractive dentition. Future
bulletins will take the narrative into and beyond the mixed dentition stage,
through to the full and natural (i.e. non-prosthodontic) rehabilitation of the
oral complex.

Generally, at the age of about 8 years, a
parent will seek professional advice. Action may need to be initiated and it is
strongly recommended that this be considered after evaluation by a competent
and knowledgeable orthodontist. Unfortunately, the child’s first port of call
is often another dental professional, whose approach to the problem may well be
along the seemingly logical line of thought described in the flow chart (Fig.
1). If this directive is carried out, the child will be dentally maimed for a
long period of time – just as long as it takes for the parents and the proactive
practitioner to arrive at the realization that the expected improvement has not
materialized and, in all probability, will not occur in the foreseeable future.
(Where ignorance rules supreme, maiming a child can be achieved despite the
best of intentions)

There is no logical basis to assume that this
extraction protocol of treatment will succeed because it does not take into
consideration 3 important factors which are characteristic of CCD,2
namely:

1.The dental age of a
CCD child is approximately 3 years delayed in relation to the chronologic age
and that of his/her contemporaries, which means that the permanent incisor
successors are too underdeveloped to expect them to erupt.

2.The eruptive
potential of the permanent teeth is greatly reduced in CCD and, while some
teeth do erupt spontaneously, they take a very long time in coming through and
their eruption is rarely complete. Most of the teeth, however, do not erupt at
all.

3.CCD patients develop
supernumerary teeth, particularly in the incisor region and these constitute
physical obstructions that prevent teeth from erupting.

Thus, by extracting teeth alone without the
intention of artificially (therapeutically) augmenting the eruptive potential
of these teeth, the patient is committed to a very long term edentulous
appearance, with no positive outcome in sight. Furthermore, because dental
development is so late, it means that active treatment aimed at erupting the
front teeth must be delayed until the child’s dental age3
reaches 7 years, which is the time that we would normally want to signs of
incisor eruption. In the CCD child, this generally corresponds to the
chronologic age of 10 years. To determine this, it is necessary to study the
radiographs to look for root development of between ½ and 2/3 of the final
expected root length of the incisors. This is the developmental stage of any
tooth when the tooth should be erupting into the mouth and it is this stage of
tooth development that is seen in recently naturally-erupted teeth in the
normal child, unaffected by CCD. Biomechanically erupting a tooth much earlier
than this risks damage to the tooth itself and the possibility of reduced root
development in the long term.

The first permanent teeth that are scheduled to
erupt in any child are the incisors and first molars. These teeth are therefore
the teeth that determine the timing of the commencement of orthodontic
treatment and, until these teeth have developed 1/2 to 2/3 their final root
length, no treatment aimed at encouraging eruption should be performed.

What about the class 3 relationship in CCD
patients?

There is a much higher prevalence of a skeletal
class 3 jaw relation in CCD patients than in the general population and this is
due, in general, to underdevelopment of the maxilla, which causes midface
hypoplasia. The class 3 relation is not always evident in the younger CCD
individual, but a negative differential growth pattern seems to accelerate at
or around puberty. Not all are affected and I have even seen a skeletal class 2
case, which became more severe during subsequent adolescent growth, although
this appears to be highly unusual.

In order to treat the skeletal class 3,
orthopedic protraction of the maxilla is essential and can be usefully achieved
without reference to the state of development of the permanent teeth. Therefore,
in the interim and while awaiting adequate root development of the unerupted
permanent incisors, protraction of the maxilla can be performed and followed
through with the intention of over-correcting the negative overjet and the
class 3 dental and skeletal relationships in the full deciduous dentition.
While this may often reduce the child’s innate class 3 growth tendency, later
growth and a mandibular class 3 dominated pubertal growth spurt or relative
growth cessation in the maxilla may still occur, which will undoubtedly indicate
the need for later orthosurgical treatment.

For speed and effectiveness, the use of face
mask protraction therapy should follow a 24/7 regimen. Wearing the face mask in
this manner, an in toto advancement of the maxilla of 5mms on each side
can be achieved in about 4 months in children of this age, as recorded in the
alteration of the relationship between the upper and lower deciduous molar
teeth and in improvement of the deciduous incisor overjet.

What sort of management protocol can be used to
achieve this level of compliance?

To influence the patient and the parent to a
sufficiently high degree of cooperation is far from easy, but it can be
achieved in a good proportion of instances – whether CCD patients or unaffected
pure skeletal 3 cases. The most important factor in the equation is to first
convince the parent of the efficacy of the appliance and the need for full time
wear. If you are able to achieve this, it will generally pay handsome dividends
in terms of clinical results. When the parent points out that the child might
not be prepared to wear the appliance outside the house, that parent (preferably
both parents) is already on your side.

Younger patients are generally less
self-conscious of the outlandish appearance of the face mask than are older
children. The other children in the kindergarten/pre-school framework and even
into the first and second grades of school are aware but less critical than
older school peers and do not ridicule or make the child feel uncomfortable. It
is also essential to recruit the kindergarten teacher to play a key supportive
role in relation to generating a positive attitude of the other children.In this age range, the child spends much time
at home and goes to bed early, which makes for the possibility of more wear
than in the older child, when full time wear is not completely achievable. Accordingly,
there is much to be gained by treating pre-school children, if they are
diagnosed sufficiently early. A child can usually be encouraged to wear the
appliance if it is simple to place and connect up with elastics to the intra-oral
mechanism. Once it is in place, a child can be very receptive to understanding
its purpose.

The face mask is possibly the most disliked and
improperly used appliance in orthodontics, specifically because of its
appearance. Therefore, it is important to make the face mask as unobtrusive and
non-restrictive as possible. This presents a problem if one is to use one of
the pre-formed face masks that are advertised in the catalogs of the various
orthodontic manufacturing companies. Since they are “one-size-fits-all”, they
are of necessity very ungainly and clumsy because of the adjustments that need
to be made to render them comfortable and effective. In the effort to make the
chin and forehead caps comfortable, they are lined with padding, which takes up
considerable space. The distance between these two plastic caps varies from
patient to patient and so it is necessary to include an adjustable screw
fitting. The plastic caps require the placement of a hinge on each to allow
adjustability of the angle of the cup to the face. In some designs, there is a
thick supporting rod that mimics the midline along the full length of the face
to join the chin and forehead caps. Mounted on this are another couple of
adjustable screw stops from which the traction elastic will be drawn. In the
vain effort to make the appliance “attractive” to the child, the plastic parts
are made in bright colors and I have noted that one company links the appliance
to a football crash helmet, in the hope that the child will be fooled into
believing that he will make the New York Giants team one day!

The alternative is to make the face mask as
simple and as inconspicuous as possible, yet strong and comfortable enough to
provide the means to the desired end. This demands doing away with the padding
in the chin and forehead caps and making them from clear transparent acrylic.
It means eliminating adjustable screws to adjust for facial height, doing away
with cap hinges, discarding adjustable screw stops and using a narrow wire
frame that does not cover the face. What is needed is a custom face mask and it
is easy to make using basic dental/orthopedic technology.4,5

Constructing a custom orthodontic/orthopedic
face mask

The only ingredients needed in the clinic are
as follows:-

1.A broad length of
very thin plastic (a.k.a. saran wrap or cling film), usually available from the
home store in rolls and intended to cover the salad bowl to prevent the
contents from drying out before the guests arrive or, alternatively, a thin plastic
bag.

2.A plaster bandage, i.e.
a roll of gauze impregnated with plaster of Paris and used in the plaster room
of any hospital orthopedic department or office.

3.An indelible pencil
or felt-tipped pen.

The patient is seated in the slightly reclined
dental chair and his/her clothing protected with a large bib.The thin plastic sheet is carefully wrapped
around the head, to completely cover the face – having first cut a hole in it,
to be placed over the nose and mouth. It is important to use a large piece of
plastic sheeting to fully encircle the head so as to have enough for the ends
to overlap each other, thereby to retain it tightly in place. A thin plastic
bag may be used, with the hole cut into it as above. The child’s head is
positioned in the headrest of the chair, which is now tipped back to almost
horizontal. Throughout the procedure, the office should be devoid of all other
people, except a parent who is sworn to good behavior. There should be no
background disturbances.

Fig. 2a, b. A plastic bib covers the patient’s clothing and
a thin plastic sheeting (saran wrap or clingfoil) has been secured round the head, with a
large hole for unimpeded nasal breathing. The wet plaster bandage has been laid
down over the face in a series of circular movements to cover the chin and
forehead. A portion of the bandage has been laid over the upper lip. The
midline is clearly marked on the plaster.

The roll of plaster bandage is soaked in a bowl
of cold water for a few seconds, until it is thoroughly wet. Its free end is
placed on the child’s face and it is laid down in a series of wide circles on
the plastic, successively over the chin, the face and the forehead as the
plaster bandage is rapidly unrolled. This is continued in a round-and-round
movement until the outer regions of the face are covered, posteriorly to the
ears, superiorly to include the forehead and inferiorly to fully enclose the
chin. A narrow strip of plaster bandage should also be taken carefully from one
side to the other, across the upper lip, making sure that it does not interfere
with the patient’s nasal airway (Fig. 2). The purpose of the several layers around the
face is to give the final plaster cast adequate bulk for strength, in the
absence of any other form of support. Do not cut the plaster bandage, but
continue placing it until the roll is finished.

Fig. 3. The separated plaster cast of another patient. Note
the chin and forehead cap markings. An outline of the forehead and chin elements,
together with a midline, were drawn on the cast before its removal.

The patient is should not be left alone while
the plaster is drying, but should be spoken to softly, ensuring that there is
no movement to disturb the setting. Before removing the cast, the anatomic
midline of the face is drawn on the plaster. The extent of the chincap and forehead cap may
also be drawn on, if desired (Fig. 3), although this is easy to define on the casting itself,
later on. Once set, the plastic should be carefully freed from behind the head
and brought forward on both sides permitting removal of the cast, which should
come clear together with its plastic lining. This operation can be performed in
a light hearted manner and will be remembered by the child as having been a fun
activity – worth photographing. It should be remembered that young children,
male or female, have facial hair which is very fine and difficult to see. If
this procedure were to be performed directly on the skin of the face, removal
of the cast would be very difficult and extremely painful for the patient – it
causes me to wince just to think about it!

The plaster cast provides an adequately
accurate impression of the face and is sent to the technician who pours it up
with the saran plastic wrap still in place, acting as a separating medium. He
then constructs a wire frame of 1.5mm wire joining the forehead area with the
chin area, taking it posteriorly to just in front of the ears, so that it is
not too obvious. He solders a cross piece 5mm labial to the upper lip, with a
small soldered hook on each side of the midline. The chin and forehead caps are
then fabricated in clear acrylic, into which are cured the ends of the wire
frame.

The intra-oral appliance

Fig. 4a. Acrylic splint with an expansion screw cured into the
acrylic, prior to cementation. Note the buccal hooks in the canine region, in a
9 year old male CCD patient.

Fig. 4b. A similar acrylic splint with transpalatal wire supports,
in an 8.5 year old female CCD patient.

Although preformed bands could be cemented to
the second deciduous molar, the teeth usually have very short clinical crowns
and brackets would need to be placed on the other teeth, together with the
construction of a palatal arch. In the present context, it is highly advantageous
to use acrylic cap splints on the posterior teeth and a metal skeleton
framework to join the two sides. Should expansion be required, a hyrax screw
can be substituted as the connector between the two sides, by curing its
extension arms into the acrylic covering the teeth (Figs. 4a, b). A wire hook or bondable
button, cured into the acrylic on the buccal side in the deciduous canine area,
may then be used as the points of application for the elastic traction to the
face mask.

The acrylic cap splints should be bonded to the
posterior teeth with glass ionomer cement, after sandblasting and/or etching
the buccal and lingual surfaces of the teeth as necessary.

Connecting it all up

Fig. 5a, b. The face mask in place. Note the minimalist dimensions
and the clear acrylic caps and their excellent adaptation to the chin and
forehead. Alteration in force direction can be made by bending the crosspiece
up or down.

A small elastic is placed on each of the hooks
or bonded buttons on the buccal side of the intra-oral appliance and, with the
face mask held in place, it is stretched to engage the soldered hooks on the
cross piece. With an elastic on each side, the face mask is held against the
face quite securely and does not require other forms of retention. The amount
of traction force used may be controlled using smaller and/or multiple
elastics (Figs. 5, 6, 7).

Fig. 6. An occlusal view of the acrylic splint in fig. 4a, showing
the traction elastics in place. There are 2 heavy 3/16” elastics on each side

Fig. 7. The mouth is opened wide to permit photography of the
intra-oral hooks for elastic traction. At rest the direction of traction was
tipped slightly downward to the horizontal plane, as seen in fig. 5

The custom face mask requires no padding, since
it is an accurate fit on the chin and forehead and, together with the use of
clear acrylic and a wire frame far back on the face, it is fairly
inconspicuous. There are no knobs, hinges and screws. As the result, the child
is much more prepared to wear the appliance and the parent much more positive
in encouraging the child to cooperate.

Even with the best bonded cap splints and good
oral hygiene, there is always a degree of gingival inflammation and sometimes the
appearance of an area of enamel decalcification due to voids created during the
cementation procedure. These may not be detected until the cap splints are
finally removed. It is therefore essential to complete this pre-eruption phase
of the treatment of CCD as quickly and as efficiently as possible, in order to
reduce the occurrence of unwanted side-effects and not to drag on the treatment
to the time when the eruption phase of the treatment is ready to begin.